The Structure and Function of the Intercalated Disc in Vertebrate Cardiac Muscle

The cellular nature of mammalian cardiac muscle was demonstrated in the 1850’s. Kolliker 1* described this cellularity from teased human embryonic preparations and Eberth 2, in the 1860’s, corroborated Kolliker‘s findings by describing the end-to-end apposition of adult cardiac muscle cells. Eberth’s interpretation was based on the finding that silver nitrate would impregnate regions between cells and delineate cell junctions. It was assumed that this procedure stained intercellular cement. Following these earlier descriptions, a number of subsequent investigators demonstrated intercalated discs in preparations of adult cardiac muscle and attributed these structures to cell boundaries (e.g. see Schweigger-Seidel 3, Zimmermann 4 and Palczewska 5).